Hallo,
I have another strange problem. It took me a while to find what caused a derailment driving into a yard. Halfway through passing the switch with a consist I got a derailment everytime. 
It turns out that the switch changes position when I am still on it!
If needed I can make a video but maybe someone has seen this before?
What causes it? Can I fix it?
I hope someone knows 
I don't know your exact situation - but i assume you are talking about some scenario, where some AI trains (and the Railworks dispatcher) are involved.
Maybe your own train started short (e.g. only loco) and you coupled some cars, making for a longer train?
Then maybe the reason is, that the dispatcher doesn't know your real train length, because she calculates the length in the beginning
(i stumbled across this situation while making a quickdrive scenario for some other route).
If this is the situation, maybe you can start with a longer t rain, initially decoupling the cars.
I had this problem with a scenario, too.
In my case the dispatcher switched the junction always under my last wagon for another AI train.
I could prevent this issue by either:
driving very very slowly thru this junction, so I had to simulate a building site ("Langsamfahrstelle")
or
by starting the scenario with a complete consist, instead of a single loko, which couples wagons later in the scenario.
i assume, its because of an AI train on its way:
maybe the AI train's route crosses your own route in some way, and as you go by, the dispatcher thought, the way is clear now.
But this should not happen if the train is still in the same signal block.
Schuster told me to check the signalling links to prevent an error ("open" or "corrupt" signal block).
But there wasn't any error and the dispatcher switched the junction ~20 metres BEFORE my last wagon hits the signal link.
There is another possibility which could cause such bugs.
What if the length of one or more wagons are faulty with a too small length in the BIN files?
Therefore the dispatcher "thinks" the consist has passed completely but it hasn't in reality yet.
Maybe it is worth doing some testing to find out what the exact problem is here.
After checking my signals I could first try another wagon type and see what happens. Thus confirming or ruling out bin.file issues
Then play with AI traffic timing and routing to see if that influences the issue.
If I can't get it to work with these methods I will change the scenario starting with a long consist.
"The devil is in the details" certainly goes for Railworks! 
It was not the wagons, it was AI traffic switching the switch in combination with the 'loco only' scenariostart.
I changed the AI traffic so that the train causing the switch to move reaches it's destination before I enter the yard.
This fixed it. I really didn't want to change the scenariostart and the traffic was only moving out of sight so this solution works best for me 
On we go with changing station names now...
